I'm surprised they don't own their own IPs. In the email world I would say that's quite important. Seems a tad casual to say "luckily they are willing to lease them"...
Yeah, me too, but it sounds like they have good reason and are working to fix it:
> Thankfully, NYI were willing to lease us those addresses, because IP range reputation is really important in the email world, and those things are hardcoded all over the place — but it has caused us complications due to more complex routing. Over the past year, we’ve been migrating to a new IP range. We’ve been running the two networks concurrently as we build up the trust reputation for the new addresses.
Might be one of those things that they did when they were small, but then got hard to change. Hopefully they will fully own their new addresses.
The thing I'm surprised about is that they only have "single path for traffic out to the internet."
I'm a little rusty in this area, but I'm pretty sure you'll have a hard time getting a direct IP allocation (vs from your transit provider) unless you are multi-homed, which apparently they were not.
There is a nice tick up in complexity when you go to advertising your address space via BGP to multiple providers.
